1. Field of the Invention
The present invention relates to a purification apparatus having UV-tubes for purifying a flowing medium, such as water, which UV-tubes are arranged in an annular space of a vessel having inlet and outlet openings for such medium and which UV-tubes are arranged around a central tube and extend parallel thereto, which central tube penetrates the vessel and comprises at one end an outflow aperture and at the other end an inflow aperture for the medium and which is flowed through by the medium in a direction opposite to the direction of flow in the annular space.
2. Description of the Prior Art
The object of such purification apparatus is to disinfect, purify and degerminate, respectively, a flowing medium such as water without the need of adding any chemicals.
A known purification apparatus (prospect "Ultra-Violet Water Purifiers" of the Ultra Dynamics Corporation, Paterson, N. J.) comprises a cylindrical vessel through which UV-tubes (also called "burners") penetrate in the longitudinal direction thereof, which vessel is provided with an inflow opening arranged oppositely to an outflow opening arranged at axially oppositely arranged ends on relative to the circumference oppositely located sides of the vessel. Thereby the complete free inner space between the tubes is flowed through by the medium, which the closer it comes to the discharge opening the more it is purified or disinfected, respectively.
The German published patent application No. 1 003 404 discloses a purifier apparatus of the above described type. The medium which is to be purified is guided upwards over a central tube and bubbles via an inlet into an annular space in the vessel in which UV-radiators are arranged uniformly along a circular line extending coaxially to the central tube. However, this apparatus does not provide a uniform radiation in the annular space and the annular space is not uniformly flowed through by the liquid to be purified such that there is no guarantee that every part of the liquid mass or volume, respectively, receives the same quantity of energy for the destruction of the microorganisms.
The German published patent application No. 1 492 336 discloses a purifier means of a different design and comprising one centrally arranged UV-radiator only.
The U.S. Pat. No. 3,865,734 discloses a disinfection or purification, respectively, device which, however, does not utilize UV-rays, and is provided with several annular spaces, each having inlets and outlets.